This application claims the priority of Swiss patent application 0968/99, filed May 25, 1999, the disclosure of which is incorporated herein by reference in its entirety.
The invention relates to a method for identifying the spinning position of a cop.
In spinning mills, the spun yarn is wound into cops. Modern spinning machines can e.g. have between 600 and 1500 spinning positions for winding a corresponding number of cops in parallel.
From the spinning machines, the cops are transported to rewinding machines, where the yarn is transferred from the cops to larger bobbins while it is classified and cleaned at the same time.
The classification of the yarn, which is carried out in the rewinding machines, yields information on the yarn""s quality. If defective yarn is found, it is desired to identify the spinning position where this yarn has been produced, such that the problem can be removed.
In order to identify the spinning position, it has been proposed to transport the cops from the spinning machine to the rewinding machine by means of caddies or pucks, wherein the caddies comprise a memory where the spinning position is stored. This is, however, an expensive solution.
As follows from the above, the term xe2x80x9ccopsxe2x80x9d designates a carrier, such as a tube, with yarn wound thereon, as it is produced in the spinning position. Such cops are also termed xe2x80x9cspinning bobbinsxe2x80x9d.
The term bobbin designates the wound up yarn as produced by the rewinding machine. Such bobbins are also designated as xe2x80x9cyarn packagesxe2x80x9d.
Hence, it is a general object of the invention to provide a method for identifying the spinning position of the cop in simple and efficient manner.
Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the method for identifying a spinning position of cops, wherein a yarn is wound on each cop in one of a plurality of spinning positions and unwound in a rewinding machine, comprises the steps of providing each cop with an individual marker and reading said marker at said rewinding machine for identifying defective spinning positions.
In a further aspect of the invention, the method for identifying a spinning position of cops, wherein each cop is wound in one of a plurality of spinning positions and unwound in a rewinding machine, comprises the steps of providing each cop with an individual marker and reading said marker after unwinding said cop for identifying defective spinning positions.
Hence, each cop is provided with a marker that can be used for identifying its spinning position. This marker can be read at the rewinding machine and/or after unwinding the cop. Hence, no special caddies or other means are required for identifying the spinning position. This is especially useful in cases where the spinning machine and the rewinding machine are not operating in-line and the cops are transported in unordered manner from the spinning machine to the rewinding machine.
The marker can in particular be applied to the tube of the cop or to the yarn of the cop.
If the marker is applied to the tube, it can e.g. consist of a bar code. This bar code should preferably be readable along a direction transversally to the longitudinal axis of the tube because less space is available parallel to this axis. The bar code can e.g. be repeated at least three times, preferably five times, along the circumference of the tube, so that it can be read out without rotating the cop.
Since the available space for applying the bar code is limited, the bar code should be short. If identification numbers of n bits are used and each bit is encoded as a narrow or wide bar code section, then the allowable identification numbers should be limited to a subset of all possible n-bit numbers. The subset is defined by those numbers that are encoded in bar codes with at least a given number k of narrow sections, wherein k greater than 0.
The marker can also be written magnetically into the tubes of the cops, preferably by using cops having a tube comprising magnetizable particles.
The marker can also be generated by dyeing the yarn, in particular by dyeing an end section of the yarn.
In an especially simple embodiment, each tube is provided with an individual marker. For identifying the spinning position of the tubes, a list is maintained separate from the tubes, e.g. in a computer, by reading the marker at each spinning position. This dispenses with the need for rewriting each marker at the spinning positions.